Our additional metal shelving shelves can be purchcased to fit shelving units that are 48" wide x 18" deep, both open and closed styles of metal shelving. They also will fit both the starter kits and/or adder kits. Each pack comes with 5 shelves and the shelf clips for installation. These shelves can hold up to 800 lbs per shelf and would be a great addition to your metal shelving units.